Don’t be database happy, not everything that can be stored in a database should be. Databases are great for storing some types of data but don’t get crazy. In some cases a flat file would be a much better solution to storing information then a database. Computers can generally process files much faster and more efficiently than a database can select that same information. If you are looking to create a directory structure or a parent child relationship don’t look to a database for answers. You should strongly consider not using a database wherever possible.
Robbalman